For those users that are planning to Jailbreak on OS 3.1.3 then I recommend adding this Cydia Source into Cydia after you jailbreak so you don't have to manually input all the Cydia Sources manually. This will automatically add all the best Cydia Sources and give you access to all the best Cydia Tweaks, Themes and Apps for FREE with just a push of a button. Follow the steps below.
1. Open Cydia
2. Tap Sources
3. Tap Edit
4. Tap Add
5. Type this url in the box (cydiasource,n e t) without the spaces and switch coma for a dot in the url.
6. Tap "Add Source"
7. Install the package labelled "All Sources".
This will give you all the best Cydia Sources to have access to all the best Tweaks, Apps and Themes for FREE..

Dear iClarified,
Thank you for your clear and easy, step by step process to jailbreak the iphone 2g. I have my one from say 6 years ago, and now its working after be left for 2-3 years. And I can give it to somebody to use.
Many thanks

http://www.rapidunlockers.com/ try this one, I unlocked my phone on very very fast (about 6 hours total) and cheap, now i can update to any version without having to worry that my phone will be locked ever again, it was the cheapest price that i found on the net only 9$